Constellation:

Character:

Genteel and reserved, Kotonoha is a student in year one of class four who is on the Student council and serves as one of the most pivotal characters in the story. A cute and noticeably well-endowed bookworm, she becomes the initial love interest of Makoto early into their second term, and with some effort from Sekai, becomes his girlfriend after she reciprocates her affection for him. While Kotonoha for the most part is calm and gentle, she has a very delicate constitution, which under stress leads to irrational culpability, delusions and even malice caused by the abuse she endures from other girls. 

Source from Wikipeida